Acidic esters of oxypropylated ethylenetetramines



Patented May 25, 1954 UNITED STATES PATENT OF ICE 2,679,512 ACIDICESTERS OF OXYPROPYLATED ETHYLENE TETRAMINES Melvin De Groote, UniversityCity, Mo., assignor to Petrolite Corporation, a corporation of Dela- NoDrawing. Application May 14, 1951, Serial No. 226,307

Claims. (Cl. 260475) The present invention is a continuation-inpart ofmy copending applications, Serial Nos. 104,801 filed July 14, 1949 (nowPatent 2,552,528, granted May 15, 1951),109,619 filed August 10, 1949(now Patent 2,552,531, granted May 15, filed July 28, 1949 (now PatentMay 15, 1951).

manufacturing said new chemical products, compounds or compositions, aswell as the products,

visothat (a) the initial polyamine reactant be free from any radicalhaving at least 8 uninterrupted carbon atoms; (b) the initial polyaminoatoms; (0) the initial polyamino reactant must be water-soluble; (d) theoxypropylation end pr duct must be water-insoluble; (e) the oxypro--pylation end product be within the molecular weight range of 2,000 to30,000 on an average statistical basis; (f) the solubilitycharacteristics of product in respect to Water must be substantially theresult of the oxypropylation step; (9) the ratio of propylene oxide perinitial reactive hydrogen atom must be withthe range of '1 to 70; (h)the initial polyamino reactant must represent not more than by weight oithe oxypropylation end product on a statistical basis; (2') the based onthe assumption of complete reaction involving the propylene oxide andinitial polyaminoatom; and (is) a carbon atom which are satisfactoryalso for demulsificatio of petroleum emulsions.

preceding provisos are i basicity of the nitrogen The present inventionis concerned with a fractional ester obtained from apolycarboxy acid anda polyhydro-xylated material obtained by the oxypropylation of apolyamino reactant.

More specifically, the present invention is concerned equivalent, 1. e.,tible to oxyalkylation.

The most suitable raw material is triethylenebination of the two,particularly triethy1enetetramine treated with one to five, six or sevenmoles of ethylene oxide.

The initial tetramine must be characterized by (it) having 4 aminonitrogen atoms and preferably all being basic; (1)) free from anyradical having 8 or more carbon atoms in an uninterrupted group; (0)must be water-soluble; and (cl) have a plurality of reactive hydrogenatoms preferably at least 3, 4 or 5.

Needless to say, the most readily. available reactant, to wit,triethylenetetramine has 6 reactive butyl, -hexyl, heptyl, like, or anaryl radical such as a phenyl radical, then and in that event the numberof reactive hydrogen atoms might be decreased to few as two or three andstill be acceptable for the instant purpose. If an alkyl radical or analicyclic radical, such as a cyclohexyl radical, or an alkyl-arylradical such as a benzyl radical, were introduced the basicity of thenitrogen atom would not be materially efsons my choice is as follows:

(a) the use of triethylenetetramine rather than any substitutedtriethylenetetramine as described;

(b) the use of triethylenetetramine after treatment with 1 to 6 moles ofethylene oxide although a modestly increased amount of ethylene oxidecan be used in light of what is said hereinafter, or

(c) the use of a derivative obtained from triethylenetetramine afterreaction with glycide, or a mixture of ethylene oxide and glycide.

.molal oxypropylation derivatives of pose of brevity further reference,will

or glycide, for pur b ma to l triethylenetetramine as illustrating theprocedure. H

regardless of what particular reactant is selected. It is not necessaryto point out, of course, that the substituted triethylenetetramines, i.e., those where an alkyl radical, alicyclic radica, arylalkyl, or arylgroup has been introduced can be subjected similarly oxide, glycide, ora combination of the two.

I also want to point out it is immaterial whether the initialoxypropylation step involves hydrogen attached to oxygen or hydrogenattached to nitrogen. The essential requirement is that it be a labileor reactive hydrogen atom. Any substituent radical present must, ofcourse, have less than 8 uninterrupted carbon atoms in a single group.

More specifically, then, the present invention is concerned withhydrophile synthetic products; said hydrophile synthetic products beingthe acidic fractional esters derived by reaction between (A) apolycarboxy acid and (B) high monomeric tetramino compounds, with theproviso that (a) the initial tetramino reactant be free from any radicalhaving at least 8 uninterrupted carbon atoms; (1)) the initial tetraminoreactant having a molecular weight of not over 800 and at least aplurality of reactive hydrogen atoms; the initial tetramino reactantmust be water-soluble; (d) theoxypropylation end product must bewater-insoluble, and kerosene-soluble; (e) the oxypropylation endproduct be within the molecular weight range of 2,500 to 30,00 on anaverage statistical basis; (I) the solubility characteristics of theoxypropylation end product in respect to water and kerosene must besubstantially the result of the oxypropylation step; (g) the ratio ofpropylene oxide per initial reactive hydrogen atom must be within therange of '1 to 70; (h) the initial tetramino reactant must represent notmorethan 20% by weight of the oxypropylation endproduct on a statisticalbasis; (i) the preceding provisos are based on the assumption ofcomplete reaction involving the propylene oxide and initialtetraminoreactant; (7') the nitrogen atoms are linked by an ethylenechain, and with the further proviso that the ratio of (A) to (B) be onemole of (A) for each hydroxylradical present in (B).

What has been said previously in. regard to the materials hereindescribed and particularly with reference to fractional esters maybe-andprobably is an over-simplication for reasons which are obvious onfurther examination. It is pointed out subsequently that prior toesterification the alkaline catalyst can be removed by addition ofhydrochloric acid. Actually the amount of hydrochloric acid added isusually sufficient and one can deliberately employ enough acid, not onlyto neutralize the alkaline catalyst but also toneutralize the aminonitrogen atom or convert it into a salt. Stated another way, a trivalentnitrogen atom is converted into a pentavalent nitrogen atom, i. e., achange involving an electrovalency indicated as follows:

to reaction with ethylene in hydroxyl value does take place sulfuricacid, a sulphonic acid,

.plicate wherein HX represents any strong acid or fairly strong acidsuch as hydrochloric acid, nitric acid, etc. in which H represents theacidic hydrogen atom and X represents the anion., Without attempting tocom the subsequent description further it is obvious then that one mighthave esters or one might convert the esters into ester salts asdescribed. Likewise another possibility is that under certain conditionsone could obtain amides. The explanation of this latter fact resides inthis observation. In as acetamide, there is always a question as towhether or not oxypropylation involves both amido hydrogen atoms so asto obtain a hundred per cent yield of the dihydroxylated compound. Thereis some evidence to at least some degree that a monohydroxylatedcompound is obtained under some circumstances with one amido hydrogenatom remaining without Another explanation which has sometimes appearedin the oxypropylation of nitrogen-containing compounds particularly suchas acetamide, is that the molecule appears to decompose under conditionsof analysis and unsaturation seems to appear simultaneously. Onesuggestion has been that one hydroxyl is lost by dehydration and thatthis ultimately causes a break in the molecule in such a way that twonew hydroxyls are formed. This is shown after a fashion in a highlyidealized manner in the following way:

CH3 CH5 H l l l HOC-C--C-XO-OO-COH H H l 1 n CHa OH; H l l I l o:-OX-O-O-C COH+ H20 H l l on; on: H 1 l I H o: -X-C--OH no-o-xo-oon H nIn th above formulas the large X is obviously not intended to signifyamlthing except the central part of a large molecule, whereas, as far asa speculative explanation is concerned, one need onlyconsidertheterminal radicals, as shown. Such suggestion. is of interest onlybecause it may be a possible explanation of how an increase which couldbe interpreted-as a decrease in molecular weight. This matter isconsidered subsequently in the finalparagraphs of Part 2. This samesituation seems to apply, in the oxypropylation of at least somepolyalkylene amines and thus is of significanoe in the instantsituation.

In the case of higher polyamines there is evidence that all theavailable hydrogen atoms are not necessarily attacked, at least undercomparatively modest oxypropylation conditions, particularly whenoxypropylation proceeds at low temperature as herein described,.forinstance, about the boiling point of water. For instance, in the case ofdiethylene triamine there is some evidence that one terminal hydrogenatom only in each of the two end groups is first attacked by propylenoxide and then th hydrogen atom attached to thecentral-nitrogen atom isattacked. It is quits possible that three long propylene oxide chainsare built up before the two remaining hydrogens are attacked and perhapsnot attacked at all. This, of course, depends on the conditions ofoxypropylation. However, analytical procedure is not entirelysatisfactory in some instances in difierentiating-betweena reactivehydrogen atom attached to nitrogen and a reactive hydrogen atom attachedto oxygen I change.

situation seems to follow.

are attacked.

If this is the case it is purely a matter of speculation at the momentbecause apparently there is mine, i, e., acylation can take placeinvolving either the hydrogen atom attached to oxygen or the hydrogenatom attached to nitrogen.

has been said and in light of what appears hereinafter.

However, in order to present the invention in.

its broades aspect it had best be re-stated as weight of theoxypropylatmn end product on a' statistical basis; (2) the precedingprovisos are based on the assumption of complete reaction involvin thepropylene oxide and initial tetramino reactant; (7') the nitrogen atomsare linked by an ethylene chain, and with the final sions of thewater-in-oil type that are commonly referred to as cut oil, roily oil,emulsified oil, etc., and which comprise fine droplets ofnaturally-occurring Waters or brines dispersed in a more or lesspermanent state throughout the oil which constitutes the continuousphase of the emulsion. The specific application is described and claimedin my co-pending application, Serial No. 226,306, filed May 14, 1951,now Patent No. 2,626,916.

and brick; as wetting agents and spreaders in the application of asphaltin road building and the like; as a flotation reagent in the flotationseparation of various aqueous suspensions containin negatively chargedparticles, such as sewage, coal Washing waste water, and various tradeWastes and the like; as germicides, insecticides, emulsifying agents,as, for example, for cosmetics, spray oils, water-repellent textilefinishes; as lubricants, etc.

For convenience, what is said hereinafter will be divided into threeparts:

Part 1 is concerned with the preparation of the oxypropylationderivative of triethylen tetramine or equivalent initial reactants;

Part 2 is concerned with the preparation of the esters from theoxypropylated derivatives; and

Part 3 is concerned with the nature of the oxypropylation derivativesinsofar that such cogeneric mixture is invariably obtained.

PART 1 For a number of Well know reasons equipment, whether laboratorysize, semi-pilot plant size,

temperature of reaction, speed of reaction, pressure during reaction,etc. For instance, oxyalkylations can be conducted at temperatures up toapproximately 200 C. with pressures in about the same range up to about200 pounds per square inch. They can be conducted also at temperaturesapproximating the boiling point of water or slightly above, as forexample to C.

the case, to wit, keeping an atmosphere of inert subjected tooxypropylation contains one, two or three points of reaction only, suchas monohydric alcohols, glycols and trials.

The, initial reactants in the instant application.

containatleastQ reactivehydrogens and for. this reasonlthere ispossibly, less advantage in using low temperature.oxypropylationratherthan high temperature oxypropylation. However, the reactions, do not go.tooslowly. and this particular procedure was used in thesubsequentexamples.

Since low pressure-low.temperature low-reactionwspeed oxypropylationsrequire considerable time, for instance, 1 to 7 days of 24 hours each tocomplete thereaction they are conducted as a rule whether 1on a,laboratory scale, pilot plant scale, or large scale,,so ,as to operateautomatically. The prior figure of seven days applies especiallytovlarge-scale operations. I have used conventional equipment with twoadded automatic features; (a) a solenoid controlled valve which shutsoflthe propylene oxide in event that the temperature gets outside apredetermined and set range,,for instance, 95? to 120 C., and (b)another solenoid valve which shuts off the propylene oxide (or for thatmatter ethylene oxide if it is being used). if the pressure gets beyonda predetermined range, such as 25 to 35 pounds. Otherwise, the equipmentis substantially the same as is commonly, employed for this purposewhere the pressure of reaction is higher, speed of reaction is higher,and time of reaction is much shorter. In such instances such automaticcontrols are not necessarily used.

Thus, in preparin the, various examples I have found it particularlyadvantageous to use laboratory equipment or pilot plant which isdesigned to permit continuous oxyalkylation whether it be oxypropylationor oxyethylation. With certain obvious changes the equipment can be usedalso to permit oxyallnylation involving. the use of glycidewhere nopressure is involved except the vapor pressure of a solvent, if any,which may have been used as a diluent.

As previously pointed out the. method of using propylene oxide isthesame as ethylene oxide. This point is emphasized only for the reasonthat the apparatus is so designed and constructedas to use eitheroxide...

The oxypropylation procedure employed in the preparation of theoxyalkylated derivatives has beernuniformly the. same, particularly inlight of the fact that a continuous-automatically-controlledprocedurewas employed. In this procedure the autoclave was a conventionalautoclave made of stainless steel and having a capacity of approximately15 gallons and a working pressure of one thousand pounds gauge pressure.This pressure obviously is far beyond any requirement as far aspropylene oxide goes unless there is a.

reaction of explosive violence involved due to accident. The autoclavewas equipped with the conventional devices and openings, such as thevariable-speed stirrer operating 50 R. P. M. to and thermocouple formechanical thermometer; emptying outlet, pressure gauge, manual ventline; charge hole for initial reactants; at least one connection forintroducing the alkylene oxide, such as propylene oxide or ethyleneoxide, tothe bottom-of the autoclave; along with suitable devices forboth cooling and heating the autoclave; such as a cooling jacket, and,preferably, coils in addition thereto, with the jacket so arranged thatitis suitable for heating with steam or cooling with water and furtherequipped with electrical heating devices. Suchautoclaves are, of course,in essencesmall-scale replicasof the usual conventional autoclaveused-in oxyalkylaat speeds from- 500 R. P. M.; thermometer well tionprocedures v Insomeinstances in exploratory preparationsan autoclavehaving a smaller, capacity, for; instance, approximately 3 liters in onecasefl and abont;1%- gallons inanother case, was use Continuousoperation, or. substantially continuous operation, ,was achieved by theuse of a separate container to hold the alkylene oxide being employed,particularly propylene oxide. In conjunction with the smallerautoclaves, the container consists. essentially of a laboratory bombhavingoa. capacity ofabout one-half gallon, or somewhat .in excessthereof. In some instances a larger. bomb was used, towit, one having acapacityoi aboutv one gallon. This bomb was equipped, also, with aninlet for charging, and an eductor tube going to the bottom of thecontainer so as-to permit discharging of alkylene oxide in the liquidphase to the autoclave. A bomb having a capacity of about 60 pounds wasused in connection with the l5-gallon autoclave. Other'conventionalequipment consists, of course, of the rupture disc, pressure gauge,sight feed glass, thermometer, connection for nitrogen for pressuringbomb, etc. The bomb was placed on a scale during use. The connectionsbetween the bomb and the autoclave were flexible stainless steel hose ortubing so that continuous weighings could be made without breaking ormaking any connections. This applies also to the nitrogen line, whichwas used to pressure the bomb reservoir. To the extent that it wasrequired, any other usualconventional procedure or addition whichprovided greater safety was used, of course, such as-safety glassprotective sreens, etc.

Attentionis directed again to what has been said previously in regardtoautomatic controls whichshut ofi the propylene oxide in eventtemperature of reaction passes out of the predetermined range or ifpressure in the autoclave passes out of predetermined range.

With .this particular arrangement practically alloxypropylations becomeuniform in that the reaction temperature was held within a few degreesof. any selectedpoint, for instance, if C. was selected as theoperatingtemperature the maximum-point would be at the most C. or 112 C., and thelowerpoint would be 95 or .possib1yl,98.", 0., Similarly, the pressurewas held ,atapproximately30 pounds within a 5- pound variation ,one wayor the other, but might drop to practically zero, especially where nosolvent such asxylene is, employed. The speed of reaction wascomparatively slow under such conditions as compared with oxyalkylationsat 200 C. Numerousreactionswere conducted in which the timevariedfromone day (24 hours) up to three. days 172 hours), for completion ofthe final member-01a series. In some. instances the reaction may take.placeinqconsiderably less time, i. e., 244 hours orless, as far as apartial oxypropylation is-concerned. The minimum time recorded was abouta 6-hour period in a single step. Reactions indicated as being completein 'l or 8 hours may have been complete in a lesser period of time inlight of the automatic equipment employed. In the addition of propyleneoxide, in the autoclave equipment as far as possible the.valves were setso all the propylene oxide if fed continuously would be added at a rateso that the predetermined amount would react within the first 5hours ofthe 8-hour period or twothirds of any shorter period. This meant that ifthe reaction was interrupted automatically for a 5 period of time forpressureto drop or temperature to drop the predetermined amount of oxidewould still be added in most instances well within the predeterminedtime period. Sometimes where the addition was a comparatively smallamount in an 8-hour period there would be an unquestionable speeding upof the reaction, by simply repeating the example and using 4, or 6 hoursinstead of 8 hours.

When operating at a comparatively high temperature, for instances,between 150 to 200 C., an unreacted alkylene oxide such as propyleneoxide, makes its presence felt in the increase in pressure or theconsistency of a high pressure. However, at a low enough temperature itmay happen that the propylene oxide goes in as a liquid. If so, and ifit remains unreacted there is, of course, an inherent danger andappropriate steps must be taken to safeguard against this possibility;if need be a sample must be withdrawn and examined for unreactedpropylene oxide. One obvious procedure, of course, is to oxypropylate ata modestly higher temperature, for instance, at 140 to 150 C. Unreactedoxide afiects determination of the acetyl or hydroxyl value of thehydroxylated compound obtained.

The higher the molecular weight of the compound, i. e., towards thelatter stages of reaction, the longer the time required to add a givenamount of oxide. One possible explanation is that the molecule, beinglarger, the opportunity for random reaction is decreased. Inversely, thelower the molecular weight the faster the reaction takes place. For thisreason, sometimes at least, increasing the concentration of the catalystdoes not appreciably speed up the reaction, particularly when. theproduct subjected to oxyalkylation has a comparatively high molecularweight. However. as has been pointed out previously. operating at a lowpressure and a low temperature even in large scale operations as much asa week or ten days time may lapse to obtain some of the higher molecularweight derivatives from monohydric or dihydric materials.

In a number of operations the counterbalance scale or dial scale holdingthe propylene oxide bomb was so set that when the predetermined amountof propylene oxide had passed into the reaction the scale movementthrough a time operating device was set for either one to two hours sothat reaction continued for 1 to 3 hours after the final addition of thelast propylene oxide and thereafter the operation was shut down. Thisparticular device is particularly suitable for use on larger eouiprnentthan laboratory size autoclaves, to wit, on semi-pilot plant or pilotplant size, as well as on large scale size. This final stirring periodis intended to avoid the presence of unreacted oxide.

In this sort of operation, of course, the temperature ran e wascontrolled automatically by either use of cooling water, steam, orelectrical heat, so as to raise or lower the temperature. The pressuringof the propylene oxide into the reaction vessel was also automaticinsofar that the feed stream was set for a slow continuous run which wasshut off in case the pressure passed a predetermined point as previouslyset out. All the points of design, construction, etc., were conventionalincluding the gases gauges, check valves and entire equipment. As far asI am aware at least two firms, and possibly three, specialize inautoclave equipment such as I have employed in the laboratory, and areprepared to furnish equipment of this same kind. Similarly pilot plantequipment is available. This point is simply made as a precaution in thedirection of safety.

Ezrample 1a The particular autoclave employed was one with a capacity ofapproximately 15 gallons or on to 350 R. P. The initial charge was 12. 2pounds of triethylenetetramine. In the initial was the result of thefact that the reactant per se was basic. The propylene oxide was addedat a rate of about 17 pounds per hour and at a comparatively moderatetemperature, to wit, 250255 F. (moderately higher than the boiling pointof water). The initial introduction of propylene oxide did Example 2a50.87 pounds of the reaction mass equivalent to 7.60 pounds of thepolyamine and 43.27 pounds of propylene oxide, and identified as Example1a, preceding, were permitted to stay in the reaction vessel and therewas added .75 pound of Example 3a 51.12 pounds of the reaction massidentified as Example 211, preceding, and equivalent to 4.10 pounds ofpolyamine, 46.62 pounds of propylene ll-pounds-pernhour. aAtthecompletion'of the reaction part of the reactionimass was withdrawnand the remainder subjected to further oxypropylationas-describedimExample 4a, immediately following.

' Example 4a 47.62 pounds of the reaction mass identified as lExample3a, preceding, and equivalent to 2.07 pounds'of polyamine, .45.35 poundsof propylene oxide and..20 pound of caustic soda, were permitted to stayin the autoclave. No additional catalyst was introduced. .Conditions inregard to temperature .and pressure were substantially the same as'in'Example la, preceding. In this instance the oxide was added in 7hours. The amount of oxideadded was.32.25-pounds. The addition was atthe:rate of approximately 6 pounds per hour. 'Atthe end of the reactionperiod part of. the reaction mass was withdrawn and the remainder of thereaction. mass subjected to further .oxypropylationas described inExample a, following.

Example 5a 59.87 "pounds of reaction mass identified. as Example4a,-preceding, and equivalent to 1.57 pounds of polyamine'; 58.15 poundsof propylene oxide, and pound'of caustic soda, were permitted to stay inthe autoclave. No additional catalyst was-added. This masswassubjected-to reaction with pounds of'propylene oxide. The conditionsofreaction -=were substantially the same'as described-in'Example 1a. asfar as temperature and'pressure were concerned. The period required-toaddthe oxide was 9 hours. The oxide wasadded at the rate of 2 poundsperhour.

' In other similar series I have used a catalyst -at the very beginning,adding some caustic soda and particularly modestly more than aboveindicated; for instance, in'a similar experiment I added initially 1.15pounds of caustic soda and continued 'oxyp'ropylat'ion-to give-amolecular weight range as high as 9,000to 10,000 and higher with ahydroxyl' mnlecular weight between 5,000

and 6,000, or higher. These-products so obtained at the higher molecular.weight range had the same characteristics as far as solubility goes, asin'Examples ia and 5a, describedin the paragraph following Table 1.

l0 ethyleneoxi'de'radicals'were introduced into the initial raw material'the initial product'ismore water soluble and one must go to'highermolecular weights 1 "to produce water-inso1ubilityandkerosene-solubility, fo1-- instance, molecular l5 weights such as-10,000to -i2,000 or-more on a theoretical :basis; and-0,000 to 8,000 or 10,000on a hydroxyl molecular weight' basis. If, however, the initialtetramine compound is treated with one or more-orperhaps several molesof butylene 20 -oxide then'-the reverse effect is obtained and it takesless propylene-oxide to'produce water-insolubility andkerosene-solubility. These productsweremf course; alkaline due'in partto the residual caustic' soda employed. This "would alsobe'thecasefifsodium methylate were used as a catalyst.

Speaking of insolubility in water or solubility inkerosene suchsolubility test can be made simply-byshaking small-amounts of thematerials in a test tube with water, for instance, using 1% to5%approximately- -based-on the amount of water present.

' Needless to say,-there is no :complete conversion of propylene oxideinto the desired hydroxylated compounds. Thisisindicated by the factthat the" theoretical "moleculanweight based on a statistical averageis'greater than the molecular weight'calculated by usual methods onbasis of acetyl 'orhydroxyl value. Actually, there is no completelysatisfactory "method for determining -molecular weights of these typesof compounds -With'a high degreeof accuracy when the molecular weightsexceed 2,000. "In some instances the acetyl value orhydroxyl valueserves as satisfactorily as an index to the molecular weight "What hasbeen said-hereinis presented'in tabular form in Table i -immediatelyfollowingwith -quiresno further=elaboration In fact, it is ilsomeaddedinformation as to molecula'r'weight and as to solubility'of thereaction product in water; xylene and kerosene.

as any 'otherprocedure, subject to the above limitations, andespecially'in the higher molecular weight range. If any difficulty isencountered in the manufacture ofth'e esters as described in 0 .Part 2the stoichiometrical. amount of acid or acid compound should be takenwhich corresponds to the indicated acetyl or hydroxyl value. This matterhas heendiscussed in the literature andis. a.matter of common knowledgeand relustrated by some of the examples appearing'in the patentpreviously mentioned.

TABLE 1 Composition Before Composition at end M W M Ex. 7 by Hyd. 2:33Pres, Time, No. Amine Oxide Oats- Theo. Amine Oxide Cata- Detero F lbs.hrs. Amt, Amt lyst', Moi. Amt, Amt, lyst, min. sq. in.

lbs lbs. lbs. Wt lbs lbs. lbs. 111.. 12. 62 972 12. 62 71. 75 l. 25 852225-230 1 35-37 5 2a-.- 7. 43. 27 1,805 7. 60 86. 52 75 1, 284 250-25535-37 6 3a. 4.10 46. 62 40 3, 335 4. 10 89. 62 40 2, 280 250-255 35-37 64a... 2.07 45. 35 I 20 5,625 2.07 77.00 .20 3,400 250-255 35-37 7 5a.--1; 57 58.15 15 7, 395 1. 57 78.15 15 4, 370 250-255 35-37 9 PART 2Examples 111 and 2a were'both soluble in water, soluble :in xylene, andinsoluble in kerosene; Example 3w was'emulsifiable to insoluble in wa-As previously pointed out the present invention is concerned withacidicesters obtained from the ter,but-so1uble inxylene'anddispersible'to in-75 oxypropylated derivatives described in Part 1,

immediately preceding, and polycarboxy acids, particularly tricarboxyacids like citric and dicarboxy acids such as adipic acid, phthalicacid, or anhydride, sucoinic acid, diglycollic sebacic acid, azelaicacid, aconitic acid, maleic acid or anhydride, citraconic acid oranhydride, maleic acid or anhydride adducts as obtained by theDiels-Alder reaction from products such as maleic anhydride, andoyclopentadiene. Such acids should be heat stable so they are notdecomposed during esterification. They may contain as many as as carbonatoms as, for example, the acids obtained by dimerization of unsaturatedfatty acids, unsaturated monocarboxy fatty acids, or unsaturatedmonocarboxy acids having 18 carbon atoms. Reference to the acid. in thehereto appended claims obviously includes the anhydrides or any otherobvious equivalents. My preference, however, is to use polycarboxy acidshaving not over 8 carbon atoms.

The production of esters including acid esters (fractional esters) frompolycarboxy acids and glycols or other hydro-xylated compounds is wellknown. In the present instance the hydroxylated compounds obtained asdescribed in Part 1, preceding, contain nitrogen atoms which may or maynot be basic. Thus, it is probable particu larly where there is a basicnitrogen atom present that salts may be formed but in any event underconditions described the salt is converted into an ester. This iscomparable to similar reactions chloric acid if employed for eliminationof the basic catalyst also combines with the basic nitrogen present toform a salt. In any event, however, such procedure does not affectconventional esterification procedure as described herein.

Needless to say, various compounds may be used such as the low molalester, the anhydride, the acyl chloride, etc. However, for purpose ofeconomy it is customary to use either the acid or the anhydride. Aconventional procedure is employed. On a laboratory scale one can employa resin pot of the kind described in U. S. Patent No. 2,499,370, datedMarch 7, 1950 to .i Groote it: Kiser, particularly with one more openingto permit the use of a porous spreader if hydrochloric acid gas is to beused as a catalyst. Such device or absorption spreader of minute Alundumthimbles which are connected to a glass tube. One can add a sulfonicacid such as para-toluene sulfonic acid as a catalyst. There is someobjection to this because in some instances there is some evidence thatthis acid catalyst tends to decompose or re- In the case ofpolydiglycollic acid, which is strongly acidic there is no need to addany catalyst. The use of hydrochloric acid gas has one advantage overpara-toluene sulfonic acid and that is that at the end of the reactionit can be out with nitrogen, whereas there is no reasonably convenientmeans available of removing the paratoluene sulfcnic acid or othersulfonic acid employed. If hydrochloric acid is employed one need onlypass the gas through at an exceedingly slow rate so as to keep thereaction mass acidic. Only a trace of acid need be present. I havemployed hydrochloric acid gas or the aqueous acid itself to eliminatethe initial basic material. My prefer ence, however, is to use nocatalyst The products obtained in Part 1 preceding may carboxy acidssuch as whatsoever.

can be separated in a phase-separating trap. As soon as the product issubstantially free from water the distillation stops. This preliminarystep can be carried out in the flask to be used for acidic solution ofthe oxypropylated derivatives described in Part 1 is then dilutedfurther with sufficient Xylene, decalin, petroleum solvent, or the like,so that one has obtained approximately a 40% solution. To this solutionthere is added drop in carboxyl value. Needless to say, if one producesa half-ester from an anhydride such as and a comprehensive table.

Other procedures for eliminating the basic employed about 200 grams ofthe polyhydroxylated compound as described in Part 1, preceding;

carried out all the water present as wat r of solution or theequivalent. Ordinarily this reemployed and found" very satisfactory isthe following:

I. B. P., 142 C. ml., 242 C. 5 ml., 200 C. ml., 244 C. 10 ml., 209 C.ml, 248 C. '15 ml., 215 C. ml., 252 C. 20 ml., 216 C. ml., 252 C. '25ml., 220? C. '75 ml., 260 C. 30 m1.,'225 C. '80 ml., 264 C. 35 ml., 230C. -1111,, 270 C. 40 234 C'. ml., 280 C. 45 ml., 237 C. '95 ml., 307 C.

After this material is added, refluxing is continued and,- of course, 18at a higher temperature, to wit, about to C. If the carboxy reactant isan ahydride needless to say no water of reaction appearsyif the carboxyreactant is an acid water of reaction should appear and should beeliminated at the above reaction temperature. If itis not eliminated Isimply separate out another 10 or 20 cc. of benzene by means of thephase-separating trap and thus raise the temperature to or C., or evento 200 C., if need be. My preference is not to go above 200 C.

The'use of such solvent is extremely satisfactory provided one does notattempt to remove the solventsubsequently except by'vacuum distillationand provided there is no objection to a little residue. Actually,'whenthese materials are used for a purpose such as'demulsification thesolvent might just as well be allowed to remain. If the 'solventis to beremoved by distillation, and particularly vacuum distillation, thenthe'high boiling aromatic petroleum solvent might well be replaced bysome more expensive solvent, such as decalin or an alkylated'decalinwhich has a 9 .9 9 9 wwecceoooc woccowoo :ncncnencncn 16 rather definiteor 'cl'ose range' boiling point. The removal of the-solvent; of course,is purely a conventional procedure and requires no elaboration. In anumber of the examples the #7-3 solvent 5 was entirely satisfactory, as,for example, in Ex- 'amples20b through 307). This is particularly thecase where the oxypropylated "derivative showed"decreasedwater-solubility. However, when the"products showedsignificant water- 10 solubility the difficulty arose that at the end ofthe esterification reaction the solvent and resultant or reaction masswas nothomogeneous. Thus, in Examples 119,27), 4b and 6b the solventisshown as-a mixture of "#7-3 solvent and 15 methanol. Approximatelytwo-thirds the solvent indicated was solvent #7-3. When all the Waterhad been eliminated methanol equal to approximately one-third thesubsequent mixture was added so as to give a single phase system. In

20 other examples, for instance, Examples 3b and 5b, methanol'itself wasnot entirely satisfactory so that instead of'adding one-third methanol(in reality 50% based on the solvent #7-3 present) there was added anequal weight of methanol and diethyl ca'rbitol which is diethyleneglycoldiethylether. Thus, the actual solvent consisted of approximatelytwo-third solvent #73, one-sixth methanol, and one-sixthdiethyleneglycol diethylether. I In Examples7b through 1% it was'foundthat xylene seemed to be the most suitable to employ. 'Die'thyleneglycoldiethylether is manufactured by the Carbide & 'Carbon ChemicalsCorporation, New York city. These solvent proportions can be variedsome- 35 what without changa'iihe object being merely to eliminate thewater in the presence of waterinsoluble solvents and then add suitablesemipolar compounds to give a homogeneous solution. Other obvioussolvents will serve.

40 Another obvious procedure; of course,ismerely to distill off asolvent such as xylene or solvent #7-3 and then dissolve the product ina semipolar solvent, such'as methanol, ethanol, propanol, etc. It ispurely a matter of convenience to first employ a non-polar solvent(waterinsoluble toeliminate the water during distillation and then add asuitable polar solvent (hydrophile) to give a single-phase system.

TABLE 2 Mol ggi? Actual Wt. gg g gg ai Eyd Polycarboxy Roactcut Carboxy230 263 852 Diglocolic Acid 117. 5 230 263 852 Oxalic Acid 108 230 263852 Maleic Anhydrldc 87. 6 230 263 v 852 Phthalic Anhydricle... 131 230263 852 Aconiiic Acid 150 230 263 852 Citraconic Anhydride. 94. 2 124174. 5 1, 284 Diglycolic A E2. 6 124 174. 5 l, 284 Oxalic Acid 77. 2 124174. 5 1, 284 Maicic Anhydridc 60 124 174. 5 1. 284 IhthalicAnhydridc... 90. 8 124 174.5 1,284 Citraconic Anhydridc. 08. 0 124 174.5 1. 284 Aconitic Acid 115 124 174. 5 1, 284 Citraconic Auhydridc. 71

67. 3 98. 4 2,280 Diglycolic Acid 46. l 67. 3 98. 4 2. 280 OX Acid 43. 567. 3 98. 4 2, 280 Maleic Anhydridc. 37. 0 67. 3 98. 4 2, 280 PhthalicAnhydridc... 51. 5 67. 3 08. 4 2, 280, Oitraconic Anhyd. 39. 4 67. 3 9B.4 2, 280 Acooitic Acid 61. 0 39. 9 60 3,400 Diglycolic Acid 31. 5 39. 966 3, 400 Oxalic Ac 31.8 39. 9 66 3, 400 Maleic Anhydridc. 23. 2 39. 966 3, 400 Phthalic Anhydridc... 35. 2 30. 0 66 3,400 CltraconicAnhydride. 27.0 39. 9 66 3, 400 Aconitic Acid 40. 0 30.4 51. 3Diglycolic Acid 24. 5 30. 4 51.3 4, 370 Oxaiic Acid 24. 7 30. 4 51.3 4,370 Maleic Anhydridc- 18.0 30.4 51.3 4, 370 Phthalic Anhydride... 27. 430. 4 51. 3 4, 370 Aconitic Acid 31. 5

TABLE 3 Ex. No. Amt. 801- Maximum Time of of Acid Solvent vent fi a gEsterificag fi Ester (grs.) C tion (bl-s.)

x 1D #7-3 111617118110] 435 130 1% 15.6. 2b -110 429 130 154 15.0. ab#7-3, methanol, diethyl 554, 554 130 1 Carbitol.

The procedure for manufacturing the esters 30 ch Can be removed byfiltration if d,

has been illustrated by preceding examples. If for any reason reactiondoes not take place in a temperature indicated or else extend the periodof time up to 12 or 16 hours if need be; (c) if necessary, use ofparatoluene sulfonic acid as a catalyst provided that the hydroxylatedcompound is not basic; ((1) if chloride or sodium sulfate is notprecipitating out. Such salt should be eliminated, at least forexploration experimentation, and can be removed by filtering. Everythingelse being equal, as th increases and the reactive hydroxyl radicalrepresents a smaller fraction of the entire molecule more difficulty isinvolved in obtaining complete esterification.

Even under the most carefully controlled conditions of oxypropylationinvolving comparatively low temperature and long time of reaction thereare formed certain compounds whose composition is still obscure. Suchside reaction products can contribute a substantial proportion of thefinal cogeneric reaction mixture. Various suggestions have been made asto the nature of these compounds, such as being cyclic polymers ofpropylene oxide, dehydration products with the appearance of a vinylradical, or isomers of propylene oxide or derivatives thereof, i. e,, ofan aldehyde, ketone, or allyl alcohol. In some instances an attempt toreact the stoichiometric amount of a polycarboxy acid with theoxypropylated derivative results in an excess of the carboxylatedreactant for the reason that apparently under conditions of reactionless reactive hydroxyl radicals are present than indicated by thehydroxyl value. Under such circumstances there is simply a residue ofthe carb'oxylic reactant e size of the molecule tetramine. If one were 0the esterification procedure can be ing an appropriately reduced ratioreactant.

repeated usof carboxylic Obviously this oxide shoul The solventemployed, if any, can be removed from the finished ester by distillationand particularly vacuum distillation. The final products or liquids aregenerally pale amber to dark reddish-amber in color, and show moderateviscosity. They can be bleached with bleaching clays, filtering chars,and the like. However, for the purpose of demulsification or the likecolor is not a factor and decolorization is not justified.

In the above instance I have permitted the solvents to remain the finalreaction mately removed all the solvents by vacuum distillation.Appearance of the final products are much the same as the polyols beforeesterification and in some instances were somewhat darker in color andhad a reddish cast and perhaps somewhat more viscous.

PART 3 In the hereto appended claims the demulsifying agent is describedas an ester obtained from a polyhydroxylated material prepared from aoncerned with a monohydroxylated material or a dihydroxylated materialone might be able to write a formula which in essence would representthe particular product. However, in a more highly hydroxylated materialthe problem b difficult for reasons which have already been indicated inconnection with oxypropylation and which can be examined by merelyconsidering for the moment a monohydroxylated material.

oxypropylation involves the same sort of varecomes increasingly moreiations as appear in preparing high molal polypropylene glycols.Propylene glycol has a secondary alcoholic radical and a primary alcoholradical. Obviously then polypropylene glycols could be obtained, atleast theoretically, in which two secondary alcoholic groups are unitedor a secondary alcohol group is united to a primary alcohol group,etherization being involved, of course, in each instance. Needless tosay, the same situation applies when one has oxypropylated polyhydricmaterials having 4 or more hydroxyls, or the obvious equivalent.

Usually no effort is made to difierentiate b..- tween oxypropylationtaking place, for example, at the primary alcohol radical or thesecondary alcohol radical. Actually, when such products are obtained,such as a high molal polypropylene glycol or the products obtained inthe manner herein described one does not obtain a single derivative suchas I-lO(RO)nI-I or --(RO) pH in which n has one and only one value, forinstance, 14, or 16, or the like. Rather, one obtains a cogenericmixture of closely related or touching homologues. These materialsinvariably have high molecular weights and cannot be separated from oneanother by any known procedure without decomposition. The proportions ofsuch mixture represent the contribution of the various individualmembers of the mixture. On a statistical basis, of course, n can beappropriately specified. For practical purposes one need only considerthe oxypropylation of a monohydric alcohol because in essence this issubstantially the mechanism involved. Even in such instances where oneis concerned with a monohydric reactant one cannot draw a single formulaand say that by following such procedure one can readily obtain 80% or90% or 100% of such compound. However, in the case of at leastmonohydric initial reactants one can readily draw the formulas of alarge number of com pounds which appear in some of the probable mixturesor can be prepared as components and mixtures which are manufacturedconventionally.

Simply by way of to the copending application of De Groote, Wirtel andPettingill, Serial No. 109,791, filed August 11, 19 59 (now Patent2,549,434, granted April 17, 1951).

However, momentarily referring again to a monohydric initial reactant itis-obvious that if one selects any such simple hydroxylated compound andsubjects such compound to oxyalkylation, such as oxyethylations, oroxypropylation, it becomes obvious that one is really producin a polymerof the alkylene oxides except for the terminal group. This isparticularly true where the amount of oxide added is comparativelylarge, for instance, 10, 20, 30, 40, or 50 units. If such compound issubjected to oxyethylation so as to introduce 30 units of ethyleneoxide, it is well known that one does not obtain a single constituentwhich, for the sake of convenience, may be indicated as RO(C2H4O')3001 1. Instead, one obtains a cogeneric mixture of closely relatedhomologues, in which the formula may be shown as the following,RO(C2H4O)1LH, wherein 1L, as far as the statistical average goes, is 30,but the individual members present in significant amount may vary frominstances where n has a value of 25, and perhaps less, to a point whereu may represent 35 or more. Such mixture is, as stated, a cogenericclosely related series of touching homologous compounds. Considerableinvestigaillustration reference is made 20 tion has been made in regardto the distribution curves for linear polymers. Attention is directed tothe article entitled Fundamental Principles of CondensationPolymerization, by Flory, which appeared in Chemical Reviews, volume 39,No. 1, page 137.

Unfortunately, as has been pointed out by Flory and other investigators,there isno satisfactory method, based on either experimental ormathematical examination, of indicating the exact proportion of thevarious members of touching homologous series which appear in cogenericcondensation products of the kind described. This means that from thepractical standpoint, i. e., the ability to describe how to make theproduct under consideration and how to repeat such production time aftertime without dlfiiulty, it is necessary to resort to some other methodof description, or else consider the value of n, in formulas such asthose which have appeared previously and which appear in the claims, asrepresenting both individual constituents in which 'n has a singledefinite value, and also with the understanding that n represents theaverage statistical value based on the assumption of completeness ofreaction.

This may be illustrated as follows: Assume that in any particularexample the molal ratio of propylene oxide per hydroxyl is 15 to 1. In ageneric formula 15 to 1 could be 10, 20, or some other amount andindicated by n. Referring to this specific case actually one obtainsproducts in which n probably varies from 10 to 20, perhaps even further.The average value, however, is 15, assuming, as previously stated, thatthe reaction is complete. The product described by the formula is bestdescribed also in terms of method of manufacture.

The significant fact in regard to the oxypropyh ated polyamines hereindescribed is that in the initial stage they are substantially allwatersoluble, for instance, up to a molecular weight of 2,500 orthereabouts. Actually, such molecular weight represents a mixture ofsome higher molecular weight materials and some lower molecular weightmaterials. The higher ones are probably water-insoluble. The product maytend to emulsify or disperse somewhat because some of the constituents,being a cogeneric mixture, are water-soluble but the bulk are insoluble.Thus one gets emulsifiability or dispersibllity as noted. Such productsare invariably xylenesoluble regardless of whether the originalreactants were or not. Reference is made to what has been saidpreviously in regard to kerosenesolubility. For example, when thetheoretical molecular weight gets somewhere past 4,000 or atapproximately 5,000 the product is kerosenesoluble and water-insoluble.These kerosenesoluble cxyalkylation products are most desirable forpreparing the esters. I have prepared hydroxylated compounds not only upto the theoretical molecular weight shown previously, i. e., about 8,000but some which were much higher. I have prepared them, not only from thepolyamine herein described, but also from oxyethylated or oxybutylatedderivatives previously referred to. The exact composition is open toquestion for reasons which are common to all oxyalkylation. It isinteresting to note, however, that the molecular weights based onhydroxyl determinations at this point were considerably less, in theneighborhood of a third or a fourth of the value at maximum point.Referring again to previous data it is to be noted, however, that 21over the range shown of kerosene-solubility the hydroxyl molecularweight has invariably stayed at two-thirds or five-eighths of thetheoretical molecular weight.

It becomes obvious when carboxylic esters are prepared from such highmolecular weight materials that the ultimate esterification productagain must be a cogeneric mixture. Likewise, it is obvious that thecontribution to the total molecular weight made by the polycarboxy acidis small. By the same token one would expect the efiectivenees of thedemulsifier to ,be comparable to the unesterified hydroxylated material.Remarkably enough, in many instances the product is distinctly better.

Having thus described my invention, what I claim as new and desire toobtain by Letters Patent, is

l. A hydrophile synthetic product which is the ester of (A) apolycarboxy acid with (B) a high molal oxypropylated monomeric tetraminocompound with the proviso that (a) the monomeric tetramino compound befree from any radical having at least 8 uninterrupted carbon atoms; (b)the monomeric tetramino compound have a molecular weight of not over 800and at least a plurality of reactive hydrogen atoms; (0) theoxypropylated monomeric tetramino compound have a molecular weight of2500 to 30,000 on an average statistical basis; (d) the ratio ofpropylene oxide per initial reactive hydrogen atom of the monomerictetramino compound be within the range of 7 to 70; (e) the monomerictetramino compound represent not more than 20% tetramino compound on astatistical basis; (I)

by weight of the oxypropylated monomeric 3 the preceding provisos beingbased on the assumption of complete reaction between the propylene oxideand the monomeric tetramino compound; (g) the nitrogen atoms are linkedby ethylene radicals; (h) the ratio of polycarboxy acid to oxypropylatedmonomeric tetramino compound being one mole of the former for eachreactive hydrogen atom of the latter; and (i) the polycarboxy acid beselected from the class consisting of isocyclic and acyclic dicarboxyand tricarboxy acids composed of oxygen, carbon and hydrogen and havingnot more than 8 carbon atoms.

2. A product as in claim 1 in which at least one of the nitrogen atomsof the oxypropylated monomeric tetramino compound is basic.

3. A product as in claim 1 in which at least two nitrogen atoms of theoxypropylene monomeric tetramino compound are basic.

4. A product as in claim 3 in which the polycarboxy acid is a dicarboxyacid.

5. A product as in claim 4 in which the monomeric tetramino compound istriethylenetetramine.

6. The product or claim 1 wherein the dicarboxy acid is diglycollicacid.

7. The product of claim 1 wherein the dicarboxy acid is maleic acid.

8. The product of claim 1 wherein the dicarboxy acid is phthalic acid.

9. The product of claim 1 wherein the dicarboxy acid is citraconic acid.

10. The product of claim 1 wherein the dicarboxy acid is succinic acid.

No references cited.

1. A HYDROPHILE SYNTHETIC PRODUCT WHICH IS THE ESTER OF (A) APOLYCARBOXY ACID WITH (B) A HIGH MOLAL OXYPROPYLATED MONOMERIC TETRAMINOCOMPOUND WITH THE PROVISO THAT (A) THE MONOMERIC TETRAMINO COMPOUND BEFREE FROM ANY RADICAL HAVING AT LEAST 8 UNINTERRUPTED CARBON ATOMS; (B)THE MONOMERIC TETRAMINO COMPOUND HAVE A MOLECULAR WEIGHT OF NOT OVER 800AND AT LEAST A PLURALITY OF REACTIVE HYDROGEN ATOMS; (C) THEOXYPROPYLATED MONOMERIC TETRAMINO COMPOUND HAVE A MOLECULAR WEIGHT OF2500 TO 30,000 ON AN AVERAGE STATISTICAL BASIS; (D) THE RATIO OFPROPYLENE OXIDE PER INITIAL REACTIVE HYDROGEN ATOM OF THE MONOMERICTETRAMINO COMPOUND BE WITHIN THE RANGE OF 7 TO 70; (E) THE MONOMERICTETRAMINO COMPOUND REPRESENT NOT MORE THAN 20% BY WEIGHT OF THEOXYPROPYLATED MONOMERIC TETRAMINO COMPOUND ON A STATISTICAL BASIS; (F)THE PRECEDING PROVISOS BEING BASED ON THE ASSUMPTION OF COMPLETEREACTION BETWEEN THE PROPYLENE OXIDE AND THE MONOMERIC TETRAMINOCOMPOUND; (G) THE NITROGEN ATOMS ARE LINKED BY ETHYLENE RADICALS; (H)THE RATIO OF POLYCARBOXY ACID TO OXYPROPYLATED MONOMERIC TETRAMINOCOMPOUND BEING ONE MOLE OF THE FORMER FOR EACH REACTIVE HYDROGEN ATOM OFTHE LATTER; AND (I) THE POLYCARBOXY ACID BE SELECTED FROM THE CLASSCONSISTING OF ISOCYCLIC AND ACYCLIC DICARBOXY AND TRICARBOXY ACIDSCOMPOSED OF OXYGEN, CARBON AND HYDROGEN AND HAVING NOT MORE THAN 3CARBON ATOMS.